Pneumatic tank with tension bar

ABSTRACT

A tank trailer may include a plurality of hoppers and a tension bar assembly extending between the hoppers.

BACKGROUND

1. Technical Field

The technical field is related generally to bulk tankers or bulk orpneumatic tanks/trailers having a plurality of hoppers. Moreparticularly, the technical field is related to such a tank or trailerhaving a tension bar extending between a pair of the hoppers.

2. Background Information

Bulk tankers and bulk tank trailers or pneumatic tank trailers areamongst the many types of vehicles used for hauling materials overhighways and the like. They typically have several hoppers or coneswhich facilitate the discharge of the bulk material from within the tankinto a discharge line through which air is pumped to discharge thematerial to a rear end of the trailer. Valve assemblies are typicallylocated at the bottom of the hoppers whereby the hoppers may be openedor closed to respectively allow the flow of the bulk particulatematerial from the hoppers into the discharge pipe and to cut off thisflow. Such tankers or trailers typically include a relativelysubstantial or large frame on which the tank/hoppers are mounted. Suchframes are relatively heavy, which for instance may decrease gas mileageor reduce the amount of cargo which may be carried in the tank whilestaying within government weight regulations.

SUMMARY

In one aspect, a tank trailer may comprise a trailer front end and atrailer back end defining therebetween a longitudinal direction; a firsthopper; a second hopper which is rearward of the first hopper; and atension bar assembly which extends between and is secured to the firstand second hoppers, and which comprises a longitudinally elongated firsttension bar extending from adjacent the first hopper to adjacent thesecond hopper.

In another aspect, a tank trailer may comprise a first hopper; a secondhopper which is rearward of the first hopper; a third hopper which isrearward of the second hopper; a first flange which is secured to andextends outward from the first hopper; a second flange which is securedto and extends outward from the second hopper; a third flange which issecured to and extends outward from the third hopper; a first tensionbar extending between and secured to first and second flanges; and asecond tension bar extending between and secured to second and thirdflanges.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

One or more sample embodiments is set forth in the followingdescription, shown in the drawings and particularly and distinctlypointed out and set forth in the appended claims.

FIG. 1 is a left side elevation view of a pneumatic tank trailer showinga piping assembly and air pump diagrammatically.

FIG. 2 is a top plan view of the trailer.

FIG. 3 is a bottom plan view of the trailer with various components suchas piping and valves removed to provide a bottom plan view of thetension bar assembly.

FIG. 4 an enlarged view of the encircled portion marked “See FIG. 4” inFIG. 3 showing part of the front end housing, part of the front hopperand a front portion of the tension bar assembly including the frontflange and a front portion of a front tension bar.

FIG. 5 an enlarged view of the encircled portion marked “See FIG. 5” inFIG. 3 showing part of the central hopper and a central portion of thetension bar assembly including the intermediate/central flange, a rearportion of a front tension bar and a front portion of a rear tensionbar.

FIG. 6 an enlarged view of the encircled portion marked “See FIG. 6” inFIG. 3 showing part of the rear end housing, part of the rear hopper anda rear portion of the tension bar assembly including the rear flange anda rear portion of a rear tension bar.

FIG. 7 is a top plan view of the tension bar assembly.

FIG. 7A is an enlarged top plan view of a front portion of the tensionbar assembly including the front flange and a front portion of the frontupper tension bar.

FIG. 7B is an enlarged top plan view of a central portion of the tensionbar assembly including the intermediate/central flange, a rear portionof the front upper tension bar and a front portion of the rear uppertension bar.

FIG. 7C is an enlarged top plan view of a rear portion of the tensionbar assembly including the rear flange and a rear portion of the rearupper tension bar.

FIG. 8A is an enlarged perspective view of a front portion of thetension bar assembly including the front flange and a front portion offront upper and lower tension bars.

FIG. 8B is an enlarged perspective view of a central portion of thetension bar assembly including the intermediate/central flange, a rearportion of front upper and lower tension bars and a front portion ofrear upper and lower tension bars.

FIG. 8C is an enlarged perspective view of a rear portion of the tensionbar assembly including the rear flange and a rear portion of rear upperand lower tension bars.

FIG. 9 is a section view taken on a central vertical longitudinallyextending plane looking rightward and showing portions of the front andintermediate hoppers and part of the tension bar assembly including thefront flange, the intermediate/central flange, the front upper and lowertension bars and a front portion of rear upper and lower tension bars.

FIG. 10 is an enlarged section view from the same perspective as FIG. 9showing a portion of the intermediate hopper and part of the tension barassembly including the intermediate/central flange, a rear portion ofthe front upper and lower tension bars and a front portion of rear upperand lower tension bars.

FIG. 11 is an enlarged section view taken on line 11-11 of FIG. 1cutting through upper and lower tension bars and showing a portion ofone of the hoppers and one of the tension bar assembly flanges from therear.

FIG. 12 is a top plan view of an alternate tension bar assembly showingtension bars which are axially offset from one another.

Similar numbers refer to similar parts throughout the drawings.

DESCRIPTION

A bulk tank trailer or pneumatic tank trailer is shown generally at 1 inFIG. 1. Trailer 1 may be a towed vehicle which is towed by a towingvehicle such as an on-road tractor (not shown) whereby trailer 1 and thetractor may form a tractor trailer rig in the form of a bulk tanker. Thefront of trailer 1 may be pivotally hitched to the rear of tractor via ahitch such as a fifth wheel hitch or the like comprising a hitch member2 of the trailer. Trailer 1 has a front 4 and a back 6 definingtherebetween a longitudinal direction. Trailer 1 further has a top 8, abottom 10 and left and right sides 12 and 14 (FIG. 2) definingtherebetween an axial direction.

For clarity, an explanation of some terms used herein is provided.Trailer 1 may have an imaginary axial center line CL (FIGS. 5, 6) orcenter plane which may be a vertical longitudinally extending planecutting through the center of the trailer midway between the left andright sides thereof. As is readily evident from the Figures, variouscomponents are axially offset or spaced from the center plane. Thedescription of trailer 1 may make reference to certain components,sides, surfaces, points and the like as being inboard or outboard of oneanother, or this may be readily apparent from the Figures even withoutspecific description. Such terms typically relate to the left or righthalves of the trailer whereby, for instance, with regard to the lefthalf (left of central plane CL), a first point which is outboard of asecond point is further to the left than the second point or furtheroutboard than the second point in a first or left outboard direction,and thus the second point is inboard of or to the right of the firstpoint. Thus, within the left half, the first point is further outboardor further from the center plane than is the second point. Likewise,with regard to the right half (right of central plane CL), a third pointwhich is outboard of a fourth point is further to the right than thefourth point or further outboard than the fourth point in a second orright outboard direction, and thus the fourth point is inboard of or tothe left of the third point. Thus, within the right half, the thirdpoint is further outboard or further from the center plane than is thefourth point.

Various surfaces may be said to face axially inward or axially outward,which may respectively mean facing generally toward or away from centerline/plane CL. Thus, on the left half of trailer 1, a surface whichfaces axially inward may be said to face generally to the right orrightward, and a surface which faces axially outward may be said to facegenerally to the left or leftward. On the right half of trailer 1, asurface which faces axially inward may be said to face generally to theleft or leftward, and a surface which faces axially outward may be saidto face generally to the right or rightward.

Similarly, various components, surfaces etc. may be said to extendaxially inward or axially outward, which may respectively mean extendinggenerally toward or away from center line/plane CL. Thus, on the lefthalf of trailer 1, a component etc. which extends axially inward may besaid to extend generally to the right or rightward, and a component,etc. which extends axially outward may be said to extend generally tothe left or leftward. On the right half of trailer 1, a component, etc.which extends axially inward may be said to extend generally to the leftor leftward, and a component etc. which extends axially outward may besaid to extend generally to the right or rightward.

Further explanation is provided with respect to references to thelongitudinal direction of trailer 1. Certain components of trailer 1 arefurther forward or rearward of other components, or may be at the samelocation along the longitudinal axis. Thus, for example, a reference totwo points, surfaces, components or the like being “at the samelongitudinal position” or “at the same longitudinal location” means thatthe two points, surfaces, components or the like are at the sameposition along the longitudinal axis while they may be at differentaxial positions, that is, spaced to the left or right of one another, orspaced upwardly or downwardly of one another. Similarly, a reference totwo points, surfaces, components or the like being “longitudinallyadjacent” one another means that the two points, surfaces, components orthe like are at or adjacent the same position along the longitudinalaxis while they may be at different axial positions or spaced upwardlyor downwardly of one another. It is also noted that the term U-shaped orU-shaped configuration may be used herein to mean an upright U-shape orU-shaped configuration and the term inverted U-shaped configuration maybe used herein to mean an upside down U-shaped configuration.

With primary reference to FIG. 1, trailer 1 may have a rigid trailerframe or structure or bulk tank assembly 16 which may include a bulktank 18 defining an interior bulk storage chamber 20; a front endhousing 22A defining a front end housing interior chamber 24A; a rearend housing 22B defining a rear end housing interior chamber 24B;several hoppers or cones 26, for example, three hoppers 26A-C; ribs 23;and front and rear slide plate assemblies 28A and 28B. Assembly 16including tank 18, end housings 22, hoppers 26, ribs 23 and slide plateassemblies 28 may be formed primarily of a metal, for instance, analuminum alloy or other suitable metal. Bulk tank 18, end housings 22,hoppers 26, and slide plate assemblies 28 and other aspects of trailer 1are described in greater detail in the patent application entitled“Pneumatic Tank Having Forward and Rearward Tangential Joint Lines” bythe same inventor filed on the same date as the present application andincorporated herein by reference.

Left and right sets of ground engaging wheels 30 may be rotatablymounted on frame/assembly 16 about respective horizontal axiallyextending axes via a suitable suspension assembly 32 which may besecured to rear end housing 22B and extend downward therefrom adjacentback or back end 6. Trailer 1 may include landing gear 34 generallyadjacent front or front end 4. Landing gear 34 may be any suitable typeknown in the art and be configured to move between a lowered position incontact with the ground for supporting the front of trailer 1 whendisconnected from the tractor or other towing vehicle and a raisedposition out of contact with the ground when trailer 1 is hitched to thetractor/towing vehicle for over the road travel.

Tank assembly 16 may include a front frame 25, which may be referred toas a hitch mounting frame (for mounting hitch member 2 thereon), alanding gear mounting frame (for mounting landing gear 34 thereon) or ahitch and landing gear mounting frame (for mounting hitch member 2 andlanding gear 34 thereon). Frame 25 may include may be a rigid structureand may be formed primarily of an aluminum alloy or other suitablemetal. Frame 25 may include various components including a front leftrail 27 and a front right rail 29. Frame 25 may be rigidly secured toand extend downward from a lower portion of front end housing 22A and alower front portion of front hopper 26A. Tank assembly 16 and suspensionassembly 32 may include a rear/suspension frame 31, which may bereferred to as a wheel mounting frame on which wheels 30 are rotatablymounted. Frame 31 may include may be a rigid structure and may be formedprimarily of an aluminum alloy or other suitable metal. Frame 31 mayinclude various components including a rear left rail 33 and a rearright rail 35. Frame 31 may be rigidly secured to and extend downwardfrom a lower portion of rear end housing 22B and a lower rear portionrear hopper 26C.

Bulk storage chamber 20 may be configured for carrying therein dryparticulate material bulk. Such material may be, for example, sand,plastic beads or pellets, or any other solid particulate materialtypically carried in bulk tank trailers, which may include food gradematerial. Interior chambers 24A and 24B may be separate from andrespectively directly in front of and directly behind interior chamber20. Hopper 26A may be the frontmost hopper and hopper 26C may be therearmost hopper with hopper 26B directly therebetween. Hopper 26B may bedirectly behind hopper 26A, while hopper 26C may be directly behindhoppers 26A and B. Trailer 1 may also be configured with two or fourhoppers, and possibly more. Center plane CL may cut through the axialcenter of each of hoppers 26 midway between the left and right sidesthereof. A plurality of hopper feed ports 36 including openable andclosable lids may be mounted on top of tank 18 above hoppers 26. Ports36 may be opened in order to receive the bulk particulate materialtherethrough to fill chamber 20 to a desired level. The lids of theports may be closed to secure the particulate material therein and keepmoisture and other material out of interior chamber 20 and to provide agenerally airtight seal. A tension bar assembly 38 may extend betweenand be secured to hoppers 26A and 26B adjacent lower ends thereof, andmay extend between and be secured to hoppers 26B and 26C adjacent lowerends thereof.

A valve assembly 40 may be secured to the bottom of each hopper 26 andmay include a valve which is operated by a control handle 42 so that thehandle and valve may be rotatably movable between an open position and aclosed position for respectively opening communication between andclosing communication between interior chamber 20 and a discharge pipe44 of an air piping assembly 46, which may be connected to anair/pneumatic pump or compressor 48 which may be mounted on the towingvehicle or tractor or elsewhere. Pump 48 is shown here on or adjacenttrailer 1 and may be upstream of piping assembly 46 and interior chamber20. Pump 48 and air piping assembly 46 may be used to facilitate thedischarge of the particulate material from within interior chamber 20through a rear end of discharge pipe 44 adjacent the rear end 6 oftrailer 1. Piping assembly 46 is shown diagrammatically in part forsimplicity and given that such piping is known in the art. In additionto discharge pipe 44, air piping assembly 46 may include several airpipes including an air inlet pipe 50 and a blow down pipe 52, such thatthe various pipes may be in fluid communication with one another andpump 48 when assembly 46 is connected to pump 48. Assembly 46 typicallyincludes several valves (not shown) which are used to control the flowof air through the various pipes of assembly 46. Air inlet pipe 50 mayhave a front inlet end configured to receive air there through to bepumped from pump 48 through the remainder of assembly 46, including anexit end of pipe 50 which may be connected to an inlet of discharge pipe44 so that air may also be pumped from the front to the back of pipe 44.Blow down pipe 52 may have an exit end connected to tank 18 adjacent thetop thereof whereby blow down pipe 52 is in direct fluid communicationwith chamber 20. Pump 48 may thus also pump air downstream through pipe52 into chamber 20 to facilitate pneumatically forcing particulatematerial in chamber 20 out of bottom exit openings of hoppers 26 throughvalves 40 when open into discharge pipe 44.

With primary reference to FIGS. 1-3, storage tank 18 is now described.Storage tank 18 may have a central section which may include hoppers 26and a top wall 54 which may have a generally inverted U-shapedconfiguration or cross section. Top wall 54 may be formed of an aluminumalloy or other suitable metal. Top wall 54 may have a front edge 56, aback edge 58, a left side bottom edge 60, a right side bottom edge 62,an inner surface 64 which faces and partially defines interior chamber20 and an outer surface 66 which faces away from chamber 20 and servesas part of the outer surface of tank 18. Front and back edges 56 and 58may serve as the front and back of the central section of trailer 1. Topwall 54 may have a top section 68, a left section 70 rigidly secured toand extending downwardly from the left side of top section 68, and aright section 72 rigidly secured to and extending downwardly from theright side of top section 68 such that left and right sections 70 and 72respectively define left and right side bottom edges 60 and 62. Top wall54 may have a longitudinally elongated peak 74 defined by top section 68adjacent top 8 of trailer 1. Peak 74 may be essentially or generallyhorizontal as viewed from the side of the trailer from adjacent frontedge 56 to adjacent back edge 58. Peak 74 may be defined by theintersection of outer surface 66 and center plane CL. Front edge 56 mayhave an inverted U-shaped configuration as viewed from the front.Similarly, back edge 58 may have an inverted U-shaped configuration asviewed from the back. Each of front and back edges 56 and 58 may bestraight as viewed from the side and may lie entirely along a respectiveupwardly extending plane which may extend axially across trailer 1. Leftside bottom edge 60 at a front end thereof may intersect the bottom leftend of front edge 56 and extend rearwardly therefrom to a rear end ofbottom edge 60, which may intersect the bottom left end of back edge 58.Similarly, right side bottom edge 62 at a front end thereof mayintersect the bottom right end of front edge 56 and extend rearwardlytherefrom to a rear end of bottom edge 62, which may intersect the rightbottom end of rear edge 58. Each of side edges 60 and 62 may extend upand down in a serpentine manner from front to rear as viewed from theside. Outer surface 66 may be convexly curved in a continuous fashion asviewed from the front or rear from bottom edge 60 to bottom edge 62.Similarly, inner surface 64 may be concavely curved in a continuousfashion as viewed from the front or rear from bottom edge 60 to bottomedge 62.

Each end housing 22A and 22B may have an end housing sidewall 76 and acap wall 78 which may be rigidly secured to sidewall 76. Each ofsidewall 76 and cap wall 78 may be formed of an aluminum alloy or othersuitable metal. It is noted here that tank 18 and various componentsincluding the end housings 22, hoppers 26 and slide plate assemblies 28may be bilaterally symmetrical about an imaginary vertical axiallyextending plane VP (FIG. 2) which may be perpendicular to plane CL andmay cut through a longitudinal center of tank 18 midway between thefront and rear ends thereof, which may be represented by the front andrear ends of end housings 22A and 22B/cap walls 78 thereof. Thus, endhousing 22A may be essentially a mirror image of end housing 22B, hopper26A may be essentially a mirror image of hopper 26C, slide plateassembly 28A may be essentially a mirror image of slide plate assembly28B, the front half of hopper 26B may be essentially a mirror image ofthe back half of hopper 26B and the front half of tank 18 may beessentially a mirror image of the back half of tank 18. It is also notedthat tank 18 and various components including the end housings 22,hoppers 26 and slide plate assemblies 28 may be bilaterally symmetricalabout central plane CL. Thus, the left half of a given end housing 22may be essentially a mirror image of the right half of the given endhousing 22, the left half ora given hopper 26 may be essentially amirror image of the right half of the given hopper 26, the left half ofa given slide plate assembly 28 may be essentially a mirror image of theright half of the given slide plate assembly 28, and the left half oftank 18 may be essentially a mirror image of the right half of tank 18.The description of components forward of plane VP may thus be similar tothat of components rearward of plane VP although various aspects may bein reverse, as will be understood from the Figures.

End housing 22A is now described with primary reference to FIGS. 1-3.Sidewall 76 may have a rear or back end or edge 80 and a front end oredge 82. Sidewall 76 may have inner and outer surfaces 84 and 86 each ofwhich may extend from end 80 to end 82. Back edge 80 may have an uppersegment 96 and a lower segment 98 which intersect one another at twointersections 100. More particularly, upper edge segment 96 may have aninverted U-shaped configuration as viewed from the rear (similar to theinverted U-shaped configuration of top wall 54 shown in FIG. 13 insection) so that upper segment 96 may have a left bottom end alsorepresented by 100 in FIG. 3 and a right bottom end also represented by100 in FIG. 4. Lower edge segment 98 may have a U-shaped configurationas viewed from the front or back, as shown in FIGS. 5 and 7. The leftintersection 100 of FIG. 3 may also represent the left top rear end oflower segment 98, while the right intersection 100 shown in FIG. 4 mayrepresent the right top rear end of lower segment 98. Edge 80 as a wholeas viewed from the rear may have a generally circular or ovalconfiguration and may be continuous so as to form a closed loop. Uppersegment 96 may be straight as viewed from the side and may lie entirelyalong an upwardly extending plane which may extend axially acrosstrailer 1 and be closely adjacent and parallel to the plane along whichfront edge 56 of top wall 54 lies, whereby these two planes may benearly coplanar. Lower segment 98 may curve in a continuous fashion asviewed from the front or as viewed from below from the left intersectionor end 100 to the right intersection or end 100. Lower segment 98 maycurve concavely in a mating fashion with the convexly curved outersurface of the hopper 26A sidewall. End housing 22A/sidewall 76 may berigidly secured to top wall 54 and hopper 26A by a weld 102. Weld 102may include an upper weld segment 102A and a lower weld segment 102Bwhich respectively secure top wall 54 and hopper 26A to end housing 22Asidewall 76. Weld 102 may be a continuous weld along the entirety ofback edge 80 and thus have a configuration similar to that of back edge80. Thus, weld 102 as viewed from the front or back may be generallycircular or oval or have a closed loop configuration. As viewed from thefront or back, upper weld segment 102A may likewise have the same typeof inverted U-shaped configuration as upper segment 96, whereas lowerweld segment 102B may have a U-shaped configuration as viewed from thefront or back which is essentially the same as that of lower segment 98.Upper weld 102A as viewed from the side may be straight and may liealong a plane which may extend axially across trailer 1 and be closelyadjacent and parallel to or coplanar with the two planes along whichfront edge 56 and upper segment 96 respectively lie. Lower weld 102B maybe continuously curved as viewed from the bottom and as viewed from theside from adjacent left intersection/ends 100 to adjacent rightintersection/ends 100.

Sidewall 76 in cross section (as viewed from the front or rear) may havea circular, oval or other closed loop configuration. End housing22A/sidewall 76 may have a longitudinally elongated peak 106 at theintersection of center plane CL and outer surface 86 along the top ofsidewall 76. Peak 106 may extend from adjacent the top of front edge 82to adjacent the top of back edge 80. Housing 22A and sidewall 76 mayalso have a longitudinally elongated base 108 at the intersection ofcenter plane CL and outer surface 86 along the bottom of sidewall 76.Base 108 may extend from adjacent the bottom of front edge 82 toadjacent the bottom of back edge 80 and lower edge segment 98. Sidewall76 may have first and second sides 110 and 112 which may respectivelyserve as left and right sides of the sidewall and end housing. Each ofsides 110 and 112 may be longitudinally elongated from front edge 82 toback edge 80.

As viewed from above (FIG. 2), end housing 22A and sidewalls 76 maytaper from back end or edge 80 to front end or edge 82 so as to becomeincreasingly narrower from back to front; left side 110 may taper orangle forward and to the right from adjacent edge 80 to adjacent edge82; right side 112 may taper or angle forward and to the left fromadjacent back edge 80 to adjacent front edge 82; and sidewall 76 may beaxially wider (from left to right perpendicular to plane CL) at oradjacent back end 80 than at or adjacent front end 82. As viewed fromthe side (FIG. 2), end housing 22A and sidewall 76 may taper fromadjacent back end 80 to adjacent front end 82 so as to narrow from backto front; housing 22A and sidewall 76 may be vertically wider at oradjacent back end 80 than at end or edge 82; peak 106 may angle or taperdownward and forward from adjacent back end 80 to adjacent end 82; andpeak 106 may angle downward and forward along a straight line at aconstant angle from adjacent back end 80 to adjacent front end 82. Asviewed from the front or rear, inner surface 84 of sidewall 76 may beconcavely curved in its entirety whereas outer surface 86 may beconvexly curved in its entirety.

With primary reference to FIGS. 1-3, cap wall 78 is now described. Asviewed from the front or rear, cap wall may, for instance, have acircular or oval configuration. Cap wall 78 may have first and secondends 114 and 116. The first or back end 114 may be an edge which hasessentially the same size and shape as edge 82 of sidewall 76 althoughedge 114 may face rearwardly while edge 82 faces forward. Cap wall 78may be secured to sidewall 76 by a weld 122 between/along edges 82 and114.

With primary reference to FIGS. 1, 3-6 and 9-11, each hopper 26 may havea hopper sidewall 124 having a top edge 126 and a bottom edge 128 whichdefines a bottom exit opening 130. Bottom edge 128 and opening 130 maybe circular as viewed from above or below. Sidewall 124 may be formed ofan aluminum alloy or other suitable metal. Each exit opening 130 isadjacent a respective valve assembly 40 and is in fluid communicationwith discharge pipe 44 when the given valve assembly 40 is in the openposition so as to allow air and particulate material within storagechamber 20 and the given hopper to flow downwardly through exit opening130 into discharge pipe 44. Each sidewall 124 may taper downwardly andinwardly from adjacent top edge 126 to adjacent bottom edge 128 andopening 130. The top edge 126 of each of hoppers 26A and 26B may have arear edge segment or portion 132 (FIG. 1) which may be U-shaped asviewed from the front or rear. The top edge 126 of each of hoppers 26Band 26C may include a front edge segment or portion 134 (FIG. 1) whichmay be U-shaped as viewed from the front or rear. Segments 132 and 134may be essentially of the same size and the same shape. Rear edgesegment 132 of hopper 26A and front edge segment 134 of hopper 26B maybe closely adjacent and face one another and be secured to one anotherby a weld 136 which may likewise be U-shaped as viewed from the front orrear and extend along the entirety of segments 132 and 134. Similarly,rear edge segment 132 of hopper 26B and front edge segment 134 of hopper26C may be closely adjacent one another and secured to one another by aweld 136 which may be U-shaped as viewed from the front or rear andextend along the entirety of segments 132 and 134.

Alternately, ribs 23 may be used, wherein each rib 23 may be U-shaped asviewed from the front or rear and extend between or along the entiretyof a given set of segments 132 and 134 which are adjacent one another.Thus, front rib 23 may extend between/along the rear edge segment 132 ofhopper 26A and front edge segment 134 of hopper 26B so that there may betwo welds 136 (FIG. 9), one of which may be between the hopper and frontrib along hopper 26A rear edge segment 132 and the front surface offront rib 23 and the other of which may be between the hopper and frontrib along hopper 26B front edge segment 134 and the rear surface offront rib 23. Similarly, rear rib 23 may extend between/along the rearedge segment 132 of hopper 26B and front edge segment 134 of hopper 26Cso that there may be two welds 136, one of which may be between thehopper and rear rib along hopper 26B rear edge segment 132 and the frontsurface of rear rib 23 and the other of which may be between the hopperand rear rib along hopper 26C front edge segment 134 and the rearsurface of rear rib 23.

Top edge 126 may also include left and right edge segments or portions138 and 140. Left side bottom edge 60 of top wall 54 may be rigidlysecured to the left edge segments 138 of hopper sidewalls 124 of each ofthe hoppers by a weld 142 which may extend in a continuous fashion alongthe entirety of bottom edge 60 or from adjacent the front end orintersection 100 of edge 60 to the back end or intersection 100 ofbottom edge 60. Right side bottom edge 62 of top wall 54 may likewise besecured to right edge segment 140 of the sidewalls of each of thehoppers by an analogous weld 142 along the right side. The top edge 126of frontmost hopper 26A/sidewall 124 may have a front edge segment orportion 144 extending from the front of left edge segment 138 to thefront of right edge segment 140. Similarly, the top edge 126 of rearmosthopper 26C/sidewall 124 may have a rear edge segment or portion alsorepresented by number 144 which extends from the back or rear end ofleft edge segment 138 to the back or rear end of right edge segment 140.

Each of hopper sidewalls 124 may have inner and outer surfaces 127 and129 each of which extends continuously from top edge 126 to bottom edge128. The outer surface 129 of each hopper 26 sidewall 124 may have afront base 131 along the front portion of sidewall 124 and a rear base133 along the rear portion of sidewall 124. Front base 131 may bedefined at the intersection between plane CL and the front of outersurface 129 from top edge 126 to bottom edge 128. Front base 131 may beor extend along a straight line and may face forward and downward. Rearbase 133 may be defined at the intersection between plane CL and theback of outer surface 129 from top edge 126 to bottom edge 128. Rearbase 133 may be or extend along a straight line and may face rearwardand downward. Each sidewall 124 and its inner and outer surfaces 127 and129 may taper or angle downwardly and inwardly from top edge 126 tobottom edge 128 and exit opening or hole 130. The front portions of eachsidewall 124 and the inner and outer surfaces 127 and 129 thereof andfront base 131 may angle downward and rearward from adjacent the frontof the given top edge 126 to adjacent a front, front end or front side135 of the given bottom edge 128 and exit opening 130, whereas the rearportion of each sidewall 124 and the inner and outer surfaces 127 and129 thereof and rear base 133 may angle downward and forward fromadjacent the back end of the given top edge 126 to a rear, rear/back endor rear/back side 137 of the given bottom edge 128 and exit opening 130,as shown in FIGS. 1, 9 and 10. Similarly, the left portion of eachsidewall 124 and the inner and outer surfaces 127 and 129 thereof mayangle downward to the right from adjacent left edge segment 138 toadjacent a left side 139 of bottom edge 128 and exit opening 130,whereas the right side of each sidewall 124 and its inner and outersurfaces 127 and 129 may angle downward to the left from adjacent rightedge segment 140 to a right side 141 of bottom edge 128 and exit opening130, as generally illustrated in FIG. 11.

Slide plate assembly 28A may be rigidly secured to end housing 22Asidewall 76 and hopper 26A by various welds so as to provide an airtightinterior chamber 20 which is separated from end housing chamber 24A byassembly 28A so that chamber 20 may extend rearward of assembly 28A andchamber 24A may extend forward of assembly 28A and so that each ofchamber 20 and chamber 24A may be partially defined by assembly 28A.More particularly, front assembly 28A may include a slide plate whichmay be secured adjacent a rear lower end thereof to the top front edgesegment 144 of front hopper 26A sidewall 124 and extend upward andforward therefrom inside front end housing 22A, and which may be securedalong left and right side edge segments thereof to inner surface 84 ofend housing 22A sidewall 76. Similarly, back assembly 28A may include aslide plate which may be secured adjacent a front lower end thereof tothe top back edge segment 144 of rear hopper 26C sidewall 124 and extendupward and rearward therefrom inside rear end housing 22B, and which maybe secured along left and right side edge segments thereof to innersurface 84 of end housing 22B sidewall 76. Chamber 20 is definedprimarily by the inner surface of top wall 54, the inner surfaces ofhopper sidewalls 124, and inner surfaces of assemblies 28A and 28B.

Tension bar assembly 38 is now described with primary reference to FIGS.4-9. Tension bar assembly 38 may include a plurality of flanges 146, aplurality of tension bars 148, a plurality of fasteners 150 and aplurality of welds 152. Flanges 146, tension bars 148, fasteners 150 andwelds 152 may be formed of a rigid metal or other rigid material.Flanges 146, bars 148 and welds 152 may be formed of an aluminum alloy.Flanges 146 may include a front flange 146A, an intermediate or centralflange 146B and a rear flange 146C. Assembly 38 may have front and rearends between assembly 38 is longitudinally elongated, wherein thesefront and rear ends may be respectively adjacent the front of frontflange 146A and the back of rear flange 146C.

Each of flanges 146 may be an annular flange defining a hopper-receivinghole 154. Each of flanges 146 may have a front or frontmost end or edge156, a back or rear or rearmost end or edge 158, a left or leftmost endor edge 160 and a right or rightmost end or edge 162. Each of flanges146 may, for example, include or be formed entirely as a plate or apiece of sheet metal. The plate or piece of sheet metal may be flat ormay be bent to form portions which are angled relative to one another.For instance, each of flanges 146 may include a plate 164 which may beflat and have an upwardly facing top surface 166, a downwardly facingbottom surface 168, an outer perimeter edge 170 and an inner perimeteredge 172 which defines the respective through hole 154. Edge 172 andhole 154 may be circular as viewed from the top or bottom. Top andbottom surfaces 166 and 168 may be flat and horizontal from outerperimeter edge 170 to inner perimeter edge 172. Edges 170 and 172 mayextend from top surface 166 to bottom surface 168.

Each plate 164 and outer perimeter edge 170 may have a front end/edgesegment 174, a rear or back end/edge segment 176, a left end/edgesegment 178 and a right end/edge segment 180. Segments 174, 176, 178 and180 may respectively define frontmost end 156, rearmost end 158,leftmost end 160 and rightmost end 162 although front end 174 of frontflange 146A plate 164 may not define frontmost end 156 as noted below.Each inner perimeter edge 172 may include a rearward facing frontportion 172A, a forward facing rear portion 172B, a rightward facingleft portion 172C and a leftward facing right portion 172D. Each innerperimeter 172 may have a frontmost point 182, a rearmost point 184, aleftmost point 186 and a rightmost point 188 which may be respectivelydefined by portions 172A, 172B, 172C and 172D. Each flange 146 and plate164 may have a front portion 190, a rear or back portion 192, a leftportion 194 and a right portion 196. Each front flange or plate portion190 may define the respective front end/edge segment 174, frontmost end156, the inner perimeter edge front portion 172A and frontmost point182. Each rear flange or plate portion 192 may define the respectiverear end/edge segment 176, rearmost end 158, the inner perimeter edgerear portion 172B and rearmost point 184. Each left flange or plateportion 194 may define the respective left end/edge segment 178,leftmost end 160, the inner perimeter edge left portion 172C andleftmost point 186. Each right flange or plate portion 196 may definethe respective right end/edge segment 180, rightmost end 162, the innerperimeter edge right portion 172D and rightmost point 188.

Front flange 146A may include first and second axially elongated legs198 and 200. Leg 198 may be an upward extending or vertical leg, and leg200 may be a forward extending or horizontal leg. Leg 198 may be securedat a bottom end or edge thereof to front end/edge 174 of flange 146Aplate 164 at an axially elongated bend, corner or intersection 202between leg 198 and plate 164. Leg 200 may be secured at a rear end oredge thereof to a top end/edge of leg 198 at an axially elongated bend,corner or intersection 204 between legs 198 and 200. Bends, corners orintersections 202 and 204 may be parallel to one another and horizontal.

Each of flanges 146 may be intersected by plane CL so that a leftportion or half of the given flange 146 lies to the left of or on theleft side of plane CL and a right portion or half of the given flange146 lies to the right of or on the right side of plane CL. Each offlanges 146 may be bilaterally symmetrical about plane CL so that theleft half of a given flange 146 is a mirror image of the right half ofthe given flange 146. More particularly, for each given flange 146, eachof front end 156, back end 158, plate 164, top surface 166, bottomsurface 168, outer perimeter edge 170, inner perimeter edge 172, hole154, front edge segment 174, rear edge segment 176, front portion 172A,rear portion 172B, frontmost point 182, rearmost point 184, frontportion 190 and back portion 192 may be intersected by plane CL so thateach of left end 160, left edge segment 178, left portion 172C, leftmostpoint 186 and left portion 194 may be to the left of or on the left sideof plane CL, and so that each of right end 162, right edge segment 180,right portion 172D, rightmost point 188 and right portion 196 may be tothe right of or on the right side of plane CL. Legs 198 and 200 of frontflange 146A may also be intersected by plane CL.

With primary reference to FIGS. 7-9, tension bars 148 may includetension bars 148A-D, wherein bar 148A may be a front upper tension bar,bar 148B may be a front lower tension bar, bar 148C may be a rear uppertension bar, and bar 148D may be a rear lower tension bar. Each tensionbar may have a front end 206, a rear or back end 208, an upwardly facingtop surface 210, a downwardly facing bottom surface 212, a leftwardfacing left side or edge 214 and a rightward facing right side or edge216. Top and bottom surfaces 210 and 212 may be parallel to one anotherand may be horizontal from adjacent front end 206 to adjacent back end208 and from adjacent left side/edge 214 to adjacent right side/edge216. Surfaces 210 and 212 may be perpendicular to plane CL. Left andright sides/edges 214 and 216 may be parallel to one another and may bevertical from adjacent front end 206 to adjacent back end 208 and fromadjacent top surface 210 to adjacent bottom surface 212. Sides/edges 214and 216 may be parallel to plane CL and perpendicular to sides/edges 214and 216.

Front and rear ends 206 and 208 (or frontmost and rearmost points of agiven tension bar) may define therebetween a longitudinal or normallength L1 (FIG. 7) of the given tension bar. Length L1 may be ahorizontal longitudinal length or distance which may be measuredhorizontally in the longitudinal direction parallel to plane CL. Leftand right sides or edges 214 and 216 (or leftmost and rightmost pointsof a given tension bar) may define therebetween a normal width W1 (FIG.7). Width W1 may be a horizontal axial maximum distance or width of agiven tension bar which may be measured horizontally in the axialdirection perpendicular to plane CL and length L1 and parallel to planeVP. Top and bottom surfaces 210 and 212 may define therebetween a normalthickness T1 (FIG. 10). Thickness T1 may be a vertical maximum distanceor thickness of a given tension bar which may be measured vertically(perpendicular to length L1 and width W1). Length L1 may, for example,be about 78 inches and may be within a range of 65 to 90 inches. WidthW1 may, for example, be about 4 inches and may be within a range of 1, 2or 3 inches to 5, 6, 7, 8, 9 or 10 inches. Thickness T1 may, forexample, be about ⅜ inch or ¼ inch and may be within a range of ¼ or ⅜inch to ½, ⅝, %, ⅞ or 1 inch. However, length L1, width W1 and thicknessT1 may vary depending on the size of the trailer, hoppers and othercomponents as well as the specific configuration of the given tensionbar, such as having different cross sectional configurations asdiscussed herein. Length L1 may be, for example, at least 5, 10 or 15times width W1; and width W1 may be 5 or 10 times thickness T1 althoughagain this may vary.

With reference to FIGS. 7A, 7B and 7C, various lengths and widths areprovided. Front flange 146A frontmost and rearmost points 156 and 158may define therebetween a normal longitudinal length L2 (FIG. 7A) offlange 146A.

Front flange 146A plate 164 front and rear ends/edges 174 and 176 maydefine therebetween a normal longitudinal length L3 (FIG. 7A) of flange146A plate 164. Central flange 146B frontmost and rearmost points 156and 158 (or central flange 146B plate 164 front and rear ends/edges 174and 176) may define therebetween a normal longitudinal length L4 (FIG.7B) of flange 146B and flange 146B plate 164. Rear flange 146C frontmostand rearmost points 156 and 158 (or rear flange 146C plate 164 front andrear ends/edges 174 and 176) may define therebetween a normallongitudinal length L5 (FIG. 7C) of flange 146C and flange 146C plate164. Front flange 146A leftmost and rightmost ends/edges/points 160 and162 may define therebetween a normal axial width W2 (FIG. 7A) of flange146A and flange 146A plate 164. Central flange 146B leftmost andrightmost points 160 and 162 may define therebetween a normal axialwidth W3 (FIG. 7B) of flange 146B and flange 146B plate 164. Rear flange146C leftmost and rightmost points 160 and 162 may define therebetween anormal axial width W4 (FIG. 7C) of flange 146C and flange 146C plate164. Any of flange or flange plate lengths L2, L3, L4 and L5 may begreater than any of flange or flange plate widths W2, W3 and W4. Tensionbar length L1 of any of the tension bars 148 may be greater than any oflengths L2, L3, L4 and L5 and any of widths W2, W3 and W4.

Each tension bar 148 may be straight as viewed from the side and/or asviewed from above or below. Each tension bar 148 may be formed entirelyas a flat longitudinally elongated plate. Bars 148 may also havedifferent configurations. For instance, a given bar 148 may be in theform of a longitudinally elongated angle iron (for instance having aV-shaped or L-shaped cross sectional configuration), a longitudinallyelongated channel (for instance having a U-shaped or C-shaped crosssectional configuration), or a solid rod or hollow tube having varioustypes of cross sectional configurations (such as circular, oval, square,rectangular and so forth).

Each of tension bars 148A-D may be intersected by plane CL so that aleft portion or half of the given tension bar lies to the left of or onthe left side of plane CL and a right portion or half of the giventension bar 148 lies to the right of or on the right side of plane CL.Each of tension bars 148 may be bilaterally symmetrical about plane CLso that the left half of a given bar 148 is a mirror image of the righthalf of the given bar 148. More particularly, for each bar 148, each offront end 206, back end 208, top surface 210, bottom surface 212 may beintersected by plane CL so that left edge 214 may be to the left of oron the left side of plane CL, and so that right edge 216 may be to theright of or on the right side of plane CL.

Front upper and lower bars 148A and 148B adjacent front ends 206 thereofmay be secured to front flange 146A/plate 164 rear portion 192 adjacentrear end 158/rear edge segment 176 via fasteners 150 and/or 152.Fasteners 150 may be, for example, rivets or pins or threaded fastenerssuch as a bolt and nut which are threadedly engaged to one another. Eachfastener 150 may extend through a set of aligned holes in bars 148A and148B and flange 146A plate 164 rear portion 192. One of fasteners 152may be a weld between flange 146A plate 164 top surface 166 and upperbar 148A adjacent front end 206. One of fasteners 152 may be a weldbetween flange 146A plate 164 bottom surface 168 and lower bar 148Badjacent front end 206. Upper bar 148A bottom surface 212 adjacent frontend 206 thereof may be closely adjacent or in contact with top surface166 of front flange 146A plate 164 rear portion 192 adjacent rear end158/rear edge segment 176. Lower bar 148B top surface 210 adjacent frontend 206 thereof may be closely adjacent or in contact with bottomsurface 168 of front flange 146A plate 164 rear portion 192 adjacentrear end 158/rear edge segment 176.

Front upper and lower bars 148A and 148B adjacent back ends 208 thereofmay be secured to central/intermediate flange 146B/plate 164 frontportion 190 adjacent front end 156/front edge segment 174 via fasteners150 and/or 152. Fasteners 150 and 152 may be the same as those discussedabove. Each fastener 150 may extend through a set of aligned holes inbars 148A and 148B and flange 146B plate 164 front portion 190. One offasteners 152 may be a weld between flange 146B plate 164 top surface166 and upper bar 148A adjacent rear end 208. One of fasteners 152 maybe a weld between flange 146B plate 164 bottom surface 168 and lower bar148B adjacent back end 208. Upper bar 148A bottom surface 212 adjacentrear end 208 thereof may be closely adjacent or in contact with topsurface 166 of intermediate flange 146B plate 164 front portion 190adjacent front end 156/front edge segment 174. Lower bar 148B topsurface 210 adjacent back end 208 thereof may be closely adjacent or incontact with bottom surface 168 of intermediate flange 146B plate frontportion 190 adjacent front end 156/front edge segment 174.

Rear upper and lower bars 148C and 148D adjacent front ends 206 thereofmay be secured to intermediate flange 146B/plate 164 rear portion 192adjacent rear end 158/rear edge segment 176 via fasteners 150 and/or152. Fasteners 150 and 152 may be the same as described above. Eachfastener 150 may extend through a set of aligned holes in bars 148C and148D and flange 146B plate 164 rear portion 192. One of fasteners 152may be a weld between flange 146B plate 164 top surface 166 and upperbar 148C adjacent front end 206. One of fasteners 152 may be a weldbetween flange 146B plate 164 bottom surface 168 and lower bar 148Dadjacent front end 206. Upper bar 148C bottom surface 212 adjacent frontend 206 thereof may be closely adjacent or in contact with top surface166 of flange 146B plate 164 rear portion 192 adjacent rear end 158/rearedge segment 176. Lower bar 148D top surface 210 adjacent front end 206thereof may be closely adjacent or in contact with bottom surface 168 offlange 146B plate 164 rear portion 192 adjacent rear end 158/rear edgesegment 176.

Rear upper and lower bars 148C and 148D adjacent back ends 208 thereofmay be secured to rear flange 146C plate 164 front portion 190 adjacentfront end 156/front edge segment 174 via fasteners 150 and/or 152.Fasteners 150 and 152 may be the same as those discussed above. Eachfastener 150 may extend through a set of aligned holes in bars 148C and148D and flange 146C plate 164 front portion 190. One of fasteners 152may be a weld between flange 146C plate 164 top surface 166 and upperbar 148C adjacent rear end 208. One of fasteners 152 may be a weldbetween flange 146C plate 164 bottom surface 168 and lower bar 148Dadjacent back end 208. Upper bar 148C bottom surface 212 adjacent rearend 208 thereof may be closely adjacent or in contact with top surface166 of rear flange 146C plate 164 front portion 190 adjacent front end156/front edge segment 174. Lower bar 148D top surface 210 adjacent backend 208 thereof may be closely adjacent or in contact with bottomsurface 168 of rear flange 146C plate front portion 190 adjacent frontend 156/front edge segment 174.

Tension bar assembly 38 may be rigidly secured to hoppers 26A-C, frontframe 25 and back frame 31. The front portion of front flange 146A maybe rigidly secured to a rear portion of front frame 25 adjacent rearends of rails 27 and 29. The front portion of flange 146A may extendfrom adjacent the rear end of left rail 27 to adjacent the rear end ofright rail 29 (and be secured to said rear ends) so that flange 146Aextends rearward beyond the back ends of frame 25 and rails 27 and 29.The rear portion of rear flange 146C may be rigidly secured to a frontportion of rear/suspension frame 31 adjacent front ends of rails 33 and35. The rear portion of flange 146C may extend from adjacent the frontend of left rail 33 to adjacent the front end of right rail 35 (and besecured to said front ends) so that flange 146C extends forward beyondthe front ends of frame 31 and rails 33 and 35. Thus, the front portionof tension bar assembly 38 may be secured to a rear portion of frontframe 25 and extend rearward to adjacent the front portion of back frame31 with the rear portion of assembly 38 secured to a front portion ofrear frame 31. Landing gear 34 may be secured to front frame 25 andextend downward therefrom. Landing gear 34 may be rearward of hitchmember 2, forward of the bottom edge 128 and exit opening 130 of fronthopper 26A, forward of the front valve 42, and longitudinally adjacentthe front end of tension bar assembly 38 and front flange 146A. Eachflange 146/plate 164 inner perimeter 172, hopper sidewall 124 bottomedge 128, hole 154 and exit opening 130 may be concentric about arespective center or vertical line or axis C which may lie in oradjacent central plane CL.

The front end 206 of each front tension bar 148A and 148B may beadjacent, rearward of, and spaced from/out of contact with the back offront hopper 26A sidewall 124 outer surface 129/rear base 133. The rearend 206 of each front tension bar 148A and 148B may be adjacent, forwardof, and spaced from/out of contact with the front of intermediate hopper26B sidewall 124 outer surface 129/front base 131. The front end 206 ofeach rear tension bar 148C and 148D may be adjacent, rearward of, andspaced from/out of contact with the back of intermediate hopper 26Bsidewall 124 outer surface 129/rear base 133. The rear end 206 of eachrear tension bar 148C and 148D may be adjacent, forward of, and spacedfrom/out of contact with the front of rear hopper 26C sidewall 124 outersurface 129/front base 131.

As viewed from the side (FIG. 1), trailer 1 may define a forward throughopening 217 (FIGS. 1, 9, 10) which extends from trailer left side 12 totrailer right side 14 above a top of tension bar assembly 38 belowhoppers 26A and 26B and the respective rear base 133 and front base 131thereof. Forward through opening 217 may extend upward from adjacentfront upper tension bar 148A top surface 210, top surface 166 of frontflange 146A plate 164 rear portion 192 and top surface 166 of centralflange 146B plate 164 front portion 190 to adjacent hopper 26A rear base133, hopper 26B front base 131, front rib 23, hopper 26A top rear edgesegment 132, hopper 26B top front edge segment 134 and the front weld orwelds 136 along said edge segments 132 and 134. As viewed from the side(FIG. 1), trailer 1 may also define a rearward through opening 217(FIGS. 1, 9, 10) which extends from trailer left side 12 to trailerright side 14 above a top of tension bar assembly 38 below hoppers 26Band 26C and the respective rear base 133 and front base 131 thereof.Rearward through opening 217 may extend upward from adjacent rear uppertension bar 148C top surface 210, top surface 166 of central flange 146Bplate 164 rear portion 192 and top surface 166 of rear flange 146C plate164 front portion 190 to adjacent hopper 26B rear base 133, hopper 26Cfront base 131, rear rib 23, hopper 26B top rear edge segment 132,hopper 26C top front edge segment 134 and the rear weld or welds 136along said edge segments 132 and 134.

The front end 206 of each front tension bar 148A and 148B may beadjacent, rearward of, and spaced from/out of contact with the back offront hopper 26A sidewall 124 outer surface 129/rear base 133. The rearend 208 of each front tension bar 148A and 148B may be adjacent, forwardof, and spaced from/out of contact with the front of intermediate hopper26B sidewall 124 outer surface 129/front base 131. The front end 206 ofeach rear tension bar 148C and 148D may be adjacent, rearward of, andspaced from/out of contact with the back of intermediate hopper 26Bsidewall 124 outer surface 129/rear base 133. The rear end 208 of eachrear tension bar 148C and 148D may be adjacent, forward of, and spacedfrom/out of contact with the front of rear hopper 26C sidewall 124 outersurface 129/front base 131.

Each of flanges 146/plates 164 may be rigidly secured to the respectivehopper 26 by a weld 218 between the given flange 146/plate 164 and thegiven hopper 26 so that the given flange extends outward from the givenhopper outer surface 129 and the given weld 218. More particularly, weld218 may extend along inner perimeter edge 172 and outer surface 129 ofsidewall 124. Weld 218 may extend along the entirety of inner perimeteredge 172 and may have a circular or other closed loop configuration asviewed from above or below. The inner perimeter 172 of a given flangeplate 164 may be closely adjacent or in contact with an associated givenhopper outer surface 129 along the entirety of inner perimeter 172. Weld218 may have a frontmost point or portion 220, a rearmost point orportion 222, a leftmost point or portion 224 and a rightmost point orportion 226, as shown in FIGS. 10 and 11, which may be respectivelyclosely adjacent inner perimeter 172 frontmost point 182, rearmost point184, leftmost point 186 and rightmost point 188. Frontmost and rearmostpoints or portion 220 and 222 may lie in or be adjacent central planeCL, whereas leftmost point or portion 224 may be spaced to the left ofplane CL and rightmost point or portion 226 may be spaced to the rightof plane CL. Several imaginary horizontal planes may be associated withtension bar assembly 38 and may be useful for purposes of description.For instance, horizontal planes HP1, HP2, HP3 and HP4 are shown in FIGS.10 and 11. Horizontal plane HP1 may be defined by top surface 210 or atopmost point of tension bar 148C (or 148A). Said another way, the topsurface 210 or topmost point of tension bar 148C (or 148A) may lie inhorizontal plane HP1. Horizontal plane HP2 may be defined by tension bar148C (or 148A) bottom surface 212, a bottommost point of tension bar148C (or 148A), flange 146B (or 146A or 146C) top surface 166 or atopmost point of flange 146B (or 146A or 146C) or plate 164 thereof; ortension bar 148C (or 148A) bottom surface 212, the bottommost point oftension bar 148C (or 148A), flange 146B (or 146A or 146C) top surface166 or the topmost point of flange 146B (or 146A or 146C) may lie inhorizontal plane HP2. Horizontal plane HP3 may be defined by tension bar148D (or 148B) top surface 210, a topmost point of tension bar 148D (or148B), flange 146B (or 146A or 146C) bottom surface 168 or a bottommostpoint of flange 146B (or 146A or 146C) or plate 164 thereof; or tensionbar 148D (or 148B) top surface 210, the topmost point of tension bar148D (or 148B), flange 146B (or 146A or 146C) bottom surface 168 or thebottommost point of flange 146B (or 146A or 146C) or plate 164 thereofmay lie in horizontal plane HP3. Horizontal plane HP4 may be defined bytension bar 148D (or 148B) bottom surface 212 or a bottommost point oftension bar 148D (or 148B); or tension bar 148D (or 148B) bottom surface212 or the bottommost point of tension bar 148D (or 148B) may lie inhorizontal plane HP4.

As shown in FIG. 10, horizontal plane HP1 may intersect hopper 26B (or26A or 26C) sidewall 124 outer surface 129 at frontmost and rearmostpoints FP1 and BP1 of outer surface 129 which lie in plane HP1;horizontal plane HP2 may intersect hopper 26B (or 26A or 26C) sidewall124 outer surface 129 at frontmost and rearmost points FP2 and BP2 ofouter surface 129 which lie in plane HP2; horizontal plane HP3 mayintersect hopper 26B (or 26A or 26C) sidewall 124 outer surface 129 atfrontmost and rearmost points FP3 and BP3 of outer surface 129 which liein plane HP3; and horizontal plane HP4 may intersect hopper 26B (or 26Aor 26C) sidewall 124 outer surface 129 at frontmost and rearmost pointsFP4 and BP4 of outer surface 129 which lie in plane HP4. Frontmostpoints FP1-FP4 may be adjacent inner perimeter 172 frontmost point 182,and frontmost points FP2 and FP3 may be closely adjacent or in contactwith inner perimeter 172 frontmost point 182. Frontmost points FP1-FP4may be adjacent, closely adjacent or in contact with weld 218 frontmostportion 220. Rearmost points BP1-BP4 may be adjacent inner perimeter 172rearmost point 184, and rearmost points BP2 and BP3 may be closelyadjacent or in contact with inner perimeter 172 rearmost point 184.Rearmost points FP1-FP4 may be adjacent, closely adjacent or in contactwith weld 218 rearmost portion 222. For a given hopper 26 and flange146, frontmost points FP1-FP4, frontmost end/edge 156, front edgesegment 174 and frontmost point 182 may be spaced forward of verticalaxis C and the front side 135 of bottom edge 128 and exit opening 130.For a given hopper 26 and flange 146, rearmost points BP1-BP4, rearmostend/edge 158, rear edge segment 176 and rearmost point 184 may be spacedrearward of vertical axis C and the rear side 137 of bottom edge 128 andexit opening 130. For a given hopper 26, as viewed from the side (FIG.10), edge 128/opening 130 and frontmost point 135, rearmost point 137,leftmost point 139 and rightmost point 141 are entirely between each offrontmost points FP1-FP4 and rearmost points BP1-BP4; and thus entirelyrearward of frontmost points FP1-FP4; and entirely forward of rearmostpoints BP1-BP4.

As shown in FIG. 11, horizontal plane HP1 may intersect hopper 26B (or26A or 26C) sidewall 124 outer surface 129 at leftmost and rightmostpoints LP1 and RP1 of outer surface 129 which lie in plane HP1;horizontal plane HP2 may intersect hopper 26B (or 26A or 26C) sidewall124 outer surface 129 at leftmost and rightmost points LP2 and RP2 ofouter surface 129 which lie in plane HP2; horizontal plane HP3 mayintersect hopper 26B (or 26A or 26C) sidewall 124 outer surface 129 atleftmost and rightmost points LP3 and RP3 of outer surface 129 which liein plane HP3; and horizontal plane HP4 may intersect hopper 26B (or 26Aor 26C) sidewall 124 outer surface 129 at leftmost and rightmost pointsLP4 and RP4 of outer surface 129 which lie in plane HP4. Leftmost pointsLP1-LP4 may be adjacent inner perimeter 172 leftmost point 186, andleftmost points LP2 and LP3 may be closely adjacent or in contact withinner perimeter 172 leftmost point 186. Leftmost points FP1-FP4 may beadjacent, closely adjacent or in contact with weld 218 leftmost portion224. Rightmost points RP1-RP4 may be adjacent inner perimeter 172rightmost point 188, and rightmost points RP2 and RP3 may be closelyadjacent or in contact with inner perimeter 172 rightmost point 188.Rightmost points RP1-RP4 may be adjacent, closely adjacent or in contactwith weld 218 rightmost portion 226. Leftmost points LP1-LP4, leftmostend/edge 160, left edge segment 178 and leftmost point 186 may be spacedto the left of central plane CL, vertical axis C and the left side 139of bottom edge 128 and exit opening 130. Rightmost points RP1-RP4,rightmost end/edge 162, right edge segment 180 and rightmost point 188may be spaced to right of central plane CL, vertical axis C and theright side 141 of bottom edge 128 and exit opening 130. For a givenhopper 26, as viewed from the rear (FIG. 11), edge 128/opening 130 andfrontmost point 135, rearmost point 137, leftmost point 139 andrightmost point 141 are entirely between each of leftmost points LP1-LP4and rightmost points RP1-RP4; and thus entirely rightward of leftmostpoints LP1-LP4; and entirely leftward of rightmost points RP1-RP4.

This paragraph provides some relationships between a given tension bar148 and the two adjacent hoppers 26 and/or two adjacent flanges 146between which the given tension bar extends. These two hoppers or pairof hoppers may be referred to in this paragraph as a forward hopper anda rearward hopper, which for instance, may represent respectivelyhoppers 26A and 26B or respectively hoppers 26B and 26C. These twoflanges or pair of flanges may be referred to in this paragraph as aforward flange and a rearward flange, which for instance, may representrespectively flanges 146A and 146B or respectively flanges 146B and146C. Each tension bar 148 including ends 206 and 208, surfaces 210 and212 and edges/sides 214 and 216 may be, as viewed from the side (FIGS.9-10), entirely between the inner perimeter frontmost point 182 of therearward flange 146 and the inner perimeter rearmost point 184 of theforward flange 146, entirely between weld 218 frontmost portion 220along the rearward hopper and flange and weld 218 rearmost portion 222along the forward hopper and flange, entirely between each of frontmostpoints FP1-FP4 of the rearward hopper and each of rearmost pointsBP1-BP4 of the forward hopper, and entirely between the front side 135of the bottom edge 128 and exit opening 130 of the rearward hopper andthe back side 137 of the bottom edge 128 and exit opening 130 of theforward hopper; and thus entirely forward of the inner perimeterfrontmost point 182 of the rearward flange 146, weld 218 frontmostportion 220 along the rearward hopper and flange, frontmost pointsFP1-FP4 of the rearward hopper, and the front side 135 of the bottomedge 128 and exit opening 130 of the rearward hopper; and entirelyrearward of the inner perimeter rearmost point 184 of the forward flange146, weld 218 rearmost portion 222 along the forward hopper and flange,rearmost points BP1-BP4 of the forward hopper, and the back side 137 ofthe bottom edge 128 and exit opening 130 of the forward hopper. Tensionbar 148 forward and rearward of the back edge segment 132 of the forwardhopper, the front edge segment 134 of the rearward hopper, the rib 23between or along said back and front edge segments 132 and 134, and thewelds 136 along said rib 23; thus, a front portion of tension bar 148including front end 206 may be forward of said back edge segment 132,front edge segment 134, rib 23 and welds 136; and a rear portion oftension bar 148 including back end 208 may be rearward of said back edgesegment 132, front edge segment 134, rib 23 and welds 136.

Each tension bar 148 including ends 206 and 208, surfaces 210 and 212and edges/sides 214 and 216 may be, as viewed from the rear (FIG. 11) orfront, entirely between leftmost end/edge 160 and rightmost end/edge162, entirely between left edge segment 178 and right edge segment 180,entirely between leftmost point 186 and rightmost point 188, entirelybetween leftmost portion 224 and rightmost portion 226, entirely betweeneach of leftmost points LP1-LP4 and each of rightmost points RP1-RP4,entirely between left and right sides 139 and 141 of bottom edge 128 andexit opening 130; and thus entirely to the right of leftmost end/edge160, left edge segment 178, leftmost point 186, leftmost portion 224,leftmost points LP1-LP4, and left side 139 of bottom edge 128 and exitopening 130; and entirely to the left of rightmost end/edge 162, rightedge segment 180, rightmost point 188, rightmost portion 226, rightmostpoints RP1-RP4 and right side 141 of bottom edge 128 and exit opening130.

FIG. 12 illustrates an alternate tension bar assembly similar to tensionbar assembly 38 showing front left and right tension bars extendingbetween flanges 146A and 146B, and rear left and right tension barsextending between flanges 146B and 146C. The front left and righttension bars are axially spaced from one another so that the right edgeof the front left bar and the left edge of the front right bar arespaced from one another and define therebetween a through space asviewed from above or below. Likewise, the rear left and right tensionbars are axially spaced from one another so that the right edge of therear left bar and the left edge of the rear right bar are spaced fromone another and define therebetween a through space as viewed from aboveor below. Each of the front and rear left bars may be entirely to theleft of and adjacent central plane CL, whereas each of the front andrear right bars may be entirely to the right of and adjacent centralplane CL, whereby plane CL may not intersect any of the tension bars ofthe alternate tension bar assembly.

It is noted that various components or terms having the same namesdescribed herein may be denoted as additional or other components, orfirst, second, third and fourth components, etc. For instance, varioushoppers may be denoted as an additional hopper or other hopper or first,second, third, fourth (etc) hoppers, and so forth. Other such componentsor terms may include, without limitation, housings, slide plateassemblies, tension bar assemblies, tension bars, flanges, plates,holes, portions, sections, wheels, walls, sidewalls, openings,intersections, ends, edges, edge segments, surfaces, peaks, bases, weldsand so forth.

While various aspects of the trailer have been described above, similaror different aspects may be described below in a similar or differentmanner. Trailer 1 may include a trailer front end and a trailer back enddefining therebetween a longitudinal direction; a first hopper; a secondhopper which is rearward of the first hopper; and a tension bar assemblywhich extends between and is secured to the first and second hoppers,and which comprises a longitudinally elongated first tension barextending from adjacent the first hopper to adjacent the second hopper.It may be the tension bar assembly comprises a first flange which issecured to and extends outward from the first hopper and which has afirst flange rear end; the tension bar assembly comprises a secondflange which is secured to and extends outward from the second hopperand which has a second flange front end which is rearward of the firstflange rear end; and the first tension bar extends between and issecured to the first and second flanges. It may be that the trailer doesnot include or is free of a rigid structure which is secured to thefirst tension bar, which extends upward from the first tension barrearward of the first flange rear end and forward of the second flangefront end, and which is secured to the first or second hopper. It may bethat the trailer does not include or is free of a metal structure whichis secured to the first tension bar, which extends upward from the firsttension bar rearward of the first flange rear end and forward of thesecond flange front end, and which is secured to the first or secondhopper by a weld. It may be that the first hopper has a first hoppersidewall having a first hopper sidewall outer surface; the second hopperhas a second hopper sidewall having a second hopper sidewall outersurface; and at least one of (a) the first flange is entirely directlybelow the first hopper sidewall outer surface, and (b) the second flangeis entirely directly below the second hopper sidewall outer surface. Itmay be that the first hopper has a first hopper back end; the secondhopper has a second hopper front end closely adjacent or in contact withthe back end of the first hopper; the first flange is entirely forwardof the first hopper back end and second hopper front end; and the secondflange is entirely rearward of the first hopper back end and secondhopper front end. It may be that the first flange has left and rightsides defining therebetween a first width; the second flange has leftand right sides defining therebetween a second width; and the firsttension bar has left and right sides defining therebetween a third widthwhich is less than each of the first and second widths. It may be that,other than the first and second flanges and any fastener which securesthe first tension bar to the first and second flanges, the trailer isfree of a rigid structure which is secured to and extends upward fromthe first tension bar and which is secured to the first or second hopperor the outer surfaces of the first and second hoppers. It may be thatthe first flange has an inner perimeter which defines a through hole;the first hopper extends through the through hole; the inner perimeterhas leftmost and rightmost points; and as viewed from the rear, thefirst tension bar is entirely to the right of the leftmost point andentirely to the left of the rightmost point. It may be that the firstflange defines a through hole having leftmost and rightmost points; thefirst hopper extends through the through hole; and as viewed from therear, the first tension bar is entirely to the right of the leftmostpoint and entirely to the left of the rightmost point. It may be thatthe first hopper has a bottom edge defining a bottom exit opening havingleftmost and rightmost points; and as viewed from the rear, the firsttension bar is entirely to the right of the leftmost point and entirelyto the left of the rightmost point. It may be that the trailer has leftand right sides; the first hopper has a first hopper sidewall having afirst hopper sidewall outer surface having a rear base; the secondhopper has a second hopper sidewall having a second hopper sidewallouter surface having a front base; and a through opening extends fromthe left side of the trailer to the right side of the trailer above atop of the tension bar assembly and below the rear and front bases. Itmay be that the trailer has a left trailer half to the left of animaginary central vertical plane and a right trailer half to the rightof the central vertical plane; the first tension bar is intersected bythe central vertical plane; the first tension bar extends from thecentral plane to the left a normal distance of no more than 1, 2, 3, 4,5 or 6 inches; and the first tension bar extends from the central planeto the left a normal distance of no more than 1, 2, 3, 4, 5 or 6 inches.It may be that the first hopper defines a first bottom exit opening; thesecond hopper defines a second bottom exit opening; the first tensionbar and the first and second exit openings are intersected by animaginary vertical plane which extends in the longitudinal direction;the first tension bar extends from the plane to the left a normaldistance of no more than 1, 2, 3, 4, 5 or 6 inches; and the firsttension bar extends from the plane to the right a normal distance of nomore than 1, 2, 3, 4, 5 or 6 inches. It may be that the first hopper hasa first hopper sidewall having a first hopper sidewall top edge, a firsthopper sidewall bottom edge and a first hopper sidewall outer surface; arear base of the first hopper sidewall outer surface is defined at anintersection between an imaginary longitudinally extending verticalplane and a back of the first hopper sidewall outer surface from thefirst hopper sidewall top edge to the first hopper sidewall bottom edge;the second hopper has a second hopper sidewall having a second hoppersidewall top edge, a second hopper sidewall bottom edge and a secondhopper sidewall outer surface; a front base of the second hoppersidewall outer surface is defined at an intersection between thevertical plane and a front of the second hopper sidewall outer surfacefrom the second hopper sidewall top edge to the second hopper sidewallbottom edge; and as viewed from the side, the first tension bar has afront end which is adjacent and spaced rearward from the rear base and aback end which is adjacent and spaced forward from the front base. Itmay be that the trailer includes a third hopper which is rearward of thesecond hopper; wherein the tension bar assembly extends between and issecured to the second and third hoppers, and comprises a longitudinallyelongated second tension bar extending from adjacent the second hopperto adjacent the third hopper.

It may also be that trailer 1 includes a first hopper; a second hopperwhich is rearward of the first hopper; a third hopper which is rearwardof the second hopper; a first flange which is secured to and extendsoutward from the first hopper; a second flange which is secured to andextends outward from the second hopper; a third flange which is securedto and extends outward from the third hopper; a first tension barextending between and secured to first and second flanges; and a secondtension bar extending between and secured to second and third flanges.It may be that trailer 1 includes a front end housing extending forwardof the first hopper and having a lower portion; a front frame secured tothe lower portion of the front end housing; a hitch member secured tothe front frame; a rear end housing extending rearward of the thirdhopper and having a lower portion; a rear frame secured to the lowerportion of the rear end housing; and a plurality of ground engagingwheels rotatably mounted on the rear frame; wherein the first flange issecured to the front frame; and the third flange is secured to the rearframe. It may also be that trailer 1 includes a front end housingextending forward of the first hopper and having a lower portion; afront frame secured to the lower portion of the front end housing; andlanding gear secured to the front frame; wherein the first hopper is afrontmost hopper and defines a bottom exit opening; and the landing gearis forward of the bottom exit opening.

In the foregoing description, certain terms have been used for brevity,clearness, and understanding. No unnecessary limitations are to beimplied therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. Moreover, the description and illustration is an example andis not limited to the exact details shown or described.

The invention claimed is:
 1. A tank trailer comprising: a trailer frontend and a trailer back end defining therebetween a longitudinaldirection; a first hopper; a second hopper which is rearward of thefirst hopper; and a tension assembly which extends between and issecured to the first and second hoppers, and which comprises a firstflange which is secured to and extends outward from the first hopper andwhich has a first flange rear end; a second flange which is secured toand extends outward from the second hopper and which has a second flangefront end which is rearward of the first flange rear end; and alongitudinally elongated first tension member secured to and extendingbetween the first and second flanges and adjacent the first hopper toadjacent the second hopper; wherein the trailer is free of a rigidstructure which is secured to the first tension member, which extendsupward from the first tension member rearward of the first flange rearend and forward of the second flange front end, and which is secured tothe first or second hopper; and wherein the trailer has a left trailerhalf to the left of an imaginary central vertical plane and a righttrailer half to the right of the central vertical plane; the firsttension member is intersected by the central vertical plane; the firsttension member extends from the central plane to the left a normaldistance of no more than 6 inches; and the first tension member extendsfrom the central plane to the right a normal distance of no more than 6inches.
 2. The tank trailer of claim 1 wherein the first hopper has afirst hopper sidewall having a first hopper sidewall outer surface; thefirst tension member has a top or bottom surface which lies in animaginary horizontal plane which intersects the first hopper sidewallouter surface at leftmost and rightmost points of first hopper sidewallouter surface which lie in the horizontal plane; and as viewed from therear, the first tension member has a left side to the right of theleftmost point and a right side to the left of the rightmost point. 3.The tank trailer of claim 1 wherein the first hopper has a first hoppersidewall having a first hopper sidewall outer surface; the second hopperhas a second hopper sidewall having a second hopper sidewall outersurface; and at least one of (a) the first flange is entirely directlybelow the first hopper sidewall outer surface, and (b) the second flangeis entirely directly below the second hopper sidewall outer surface. 4.The tank trailer of claim 1 wherein the first hopper has a first hopperback end; the second hopper has a second hopper front end closelyadjacent or in contact with the back end of the first hopper; the firstflange is entirely forward of the first hopper back end and secondhopper front end; and the second flange is entirely rearward of thefirst hopper back end and second hopper front end.
 5. The tank trailerof claim 1 wherein the first flange has left and right sides definingtherebetween a first width; the second flange has left and right sidesdefining therebetween a second width; and the first tension member hasleft and right sides defining therebetween a third width which is lessthan each of the first and second widths.
 6. The tank trailer of claim 1wherein, other than the first and second flanges and any fastener whichsecures the first tension member to the first and second flanges, thetrailer is free of a rigid structure which is secured to and extendsupward from the first tension member and which is secured to the firstor second hopper.
 7. The tank trailer of claim 1 wherein the firstflange has an inner perimeter which defines a through hole; the firsthopper extends through the through hole; the inner perimeter hasleftmost and rightmost points; and as viewed from the rear, the firsttension member is entirely to the right of the leftmost point andentirely to the left of the rightmost point.
 8. The tank trailer ofclaim 1 wherein the first flange defines a through hole having leftmostand rightmost points; the first hopper extends through the through hole;and as viewed from the rear, the first tension member is entirely to theright of the leftmost point and entirely to the left of the rightmostpoint.
 9. The tank trailer of claim 1 wherein the first hopper has abottom edge defining a bottom exit opening having leftmost and rightmostpoints; and as viewed from the rear, the first tension member isentirely to the right of the leftmost point and entirely to the left ofthe rightmost point.
 10. The tank trailer of claim 1 wherein the trailerhas left and right sides; the first hopper has a first hopper sidewallhaving a first hopper sidewall outer surface having a rear base; thesecond hopper has a second hopper sidewall having a second hoppersidewall outer surface having a front base; and a through openingextends from the left side of the trailer to the right side of thetrailer above a top of the tension assembly and below the rear and frontbases.
 11. The tank trailer of claim 1 wherein the first hopper has afirst hopper sidewall having a first hopper sidewall top edge, a firsthopper sidewall bottom edge and a first hopper sidewall outer surface; arear base of the first hopper sidewall outer surface is defined at anintersection between an imaginary longitudinally extending verticalplane and a back of the first hopper sidewall outer surface from thefirst hopper sidewall top edge to the first hopper sidewall bottom edge;the second hopper has a second hopper sidewall having a second hoppersidewall top edge, a second hopper sidewall bottom edge and a secondhopper sidewall outer surface; a front base of the second hoppersidewall outer surface is defined at an intersection between thevertical plane and a front of the second hopper sidewall outer surfacefrom the second hopper sidewall top edge to the second hopper sidewallbottom edge; and as viewed from the side, the first tension member has afront end which is adjacent and spaced rearward from the rear base and aback end which is adjacent and spaced forward from the front base. 12.The tank trailer of claim 1 further comprising a third hopper which isrearward of the second hopper; wherein the tension assembly extendsbetween and is secured to the second and third hoppers, and comprises alongitudinally elongated second tension member extending from adjacentthe second hopper to adjacent the third hopper.
 13. The tank trailer ofclaim 1 further comprising: a third hopper which is rearward of thesecond hopper; and a third flange which is secured to and extendsoutward from the third hopper; a second tension member extending betweenand secured to second and third flanges; and wherein the trailer is freeof a rigid structure which is secured to the second tension member,which extends upward from the second tension member rearward of thesecond flange and forward of the third flange, and which is secured tothe second or third hopper.
 14. The tank trailer of claim 13 furthercomprising a front end housing extending forward of the first hopper andhaving a lower portion; a front frame secured to the lower portion ofthe front end housing; a hitch member secured to the front frame; a rearend housing extending rearward of the third hopper and having a lowerportion; a rear frame secured to the lower portion of the rear endhousing; and a plurality of ground engaging wheels rotatably mounted onthe rear frame; wherein the first flange is secured to the front frame;and the third flange is secured to the rear frame.
 15. The tank trailerof claim 13 further comprising a front end housing extending forward ofthe first hopper and having a lower portion; a front frame secured tothe lower portion of the front end housing; and landing gear secured tothe front frame; wherein the first hopper is a frontmost hopper anddefines a bottom exit opening; and the landing gear is forward of thebottom exit opening.
 16. The tank trailer of claim 13 wherein the firsttension member is a first tension bar; and the second tension member isa second tension bar.
 17. The tank trailer of claim 1 wherein the firsttension member is a first tension bar.
 18. A tank trailer comprising: atrailer front end and a trailer back end defining therebetween alongitudinal direction; a first hopper; a second hopper which isrearward of the first hopper; and a tension assembly which extendsbetween and is secured to the first and second hoppers, and whichcomprises a first flange which is secured to and extends outward fromthe first hopper and which has a first flange rear end; a second flangewhich is secured to and extends outward from the second hopper and whichhas a second flange front end which is rearward of the first flange rearend; and a longitudinally elongated first tension member secured to andextending between the first and second flanges and adjacent the firsthopper to adjacent the second hopper; wherein the trailer is free of arigid structure which is secured to the first tension member, whichextends upward from the first tension member rearward of the firstflange rear end and forward of the second flange front end, and which issecured to the first or second hopper; and wherein the first hopperdefines a first bottom exit opening; the second hopper defines a secondbottom exit opening; the first tension member and the first and secondexit openings are intersected by an imaginary vertical plane whichextends in the longitudinal direction; the first tension member extendsfrom the plane to the left a normal distance of no more than 6 inches;and the first tension member extends from the plane to the right anormal distance of no more than 6 inches.